Questions of sustainability give challenges to education. What does this perspective mean to the purpose of education? The relation between knowledge, politics and ethics is complex and sensitive (Lundegård and Wickman, 2007; Rudsberg and Öhman, 2010; Scott and Gough, 2003). This paper is a part of a PhD thesis. The overall aim of my thesis is to problematize how different goals of education for sustainable development (ESD) as social change, qualification and development of personal opinions, are interrelated and articulated in teachers’ discussions about education and sustainability. The challenge of sustainable questions in relation to the aims of education is problematized. In this paper the question of how teachers articulate qualification in relation to other goals is in focus. In the international policy discourse on ESD, issues of sustainability are mainly seen as matters of individual learning and processes of social change, framed as a challenge for individuals to develop the proper knowledge, behaviour and competences. (Van Poeck & Vandenabeele 2012; Biesta 2004; Simson and Masschelein 2010). However, to translate education into a process of qualification and of teaching people how to behave as active participants in a democratic society is not unproblematic (Van Poeck &Vandenabeele 2012; Jickling and Wals 2008). To be able to problematize this further, examples from social practices are used, where teachers in discussions with colleagues develops what they see as important in ESD. In a related study in my thesis (Hasslöf & Malmberg, in manuscript) the teachers articulated critical thinking as an emerging key competence. A broad definition of critical thinking revealed with different and interfering goals. In this paper the aim is to view those articulations of critical thinking in relation to how “qualification” is articulated in relation to other aims as subjectification and socialisation. The following research question is posed, with a special focus on “qualification”: • In what way are the teachers articulating critical thinking in relation to different functions of education, when discussing education and sustainability? The analyses builds upon the distinction Gert Biesta (2009) makes between three different functions of education. He refers to three functions as qualification, socialization and subjectification. According to Biesta (2009) the three functions are mutually affecting each other in education. But when we discuss our purpose of education -i.e. what makes up a good education- it is of importance to distinguish the three functions. The function of qualification refers to how knowledge, skills and understanding allow students to “do something”, the contribution education makes to development and growth and for political and cultural literacy. Through its socialising function education inserts individuals into existing ways of doing and being. Socialisation serves to introduce newcomers into particular social practices, to become parts of existing ‘orders’. Subjectification on the other hand has to do with the uniqueness of humans. It is a way to express agency and” independence” to the orders of a community. The function of subjectivity is addressing the issue of how to become a subject of action and responsibility for another being. In this paper the meaning making of qualification is in special focus. To analyse this meaning making process, tools from discourse theory is used.